<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>
    .stretching-column {
      overflow: hidden;
      border: 1px solid #09f;
      width: 600px;
      height: 300px;
      line-height: 20px;
      font-size: 16px;
      color: #f90;
    }
    .stretching-column .left {
      overflow: hidden;
      float: left;
      position: relative;
      height: 100%;
    }
    .stretching-column .right {
      overflow: hidden;
      padding: 10px;
      height: 100%;
      background-color: #f0f0f0;
      word-break: break-all;
    }

    .resize-bar {
      overflow: scroll;
      width: 200px;
      height: 100%;
      opacity: 0;
      resize: horizontal;
    }
    .resize-bar::-webkit-scrollbar {
      width: 200px;
      height: 100%;
    }
    .resize-bar:hover ~ .resize-line, .resize-bar:active ~ .resize-line {
      border-left: 1px dashed #09f;
    }

    .resize-line {
      position: absolute;
      right: 0;
      top: 0;
      bottom: 0;
      border-left: 1px solid #ccc;
      border-right: 2px solid #f0f0f0;
      pointer-events: none;
    }

    .resize-text {
      overflow-x: hidden;
      position: absolute;
      left: 0;
      right: 5px;
      top: 0;
      bottom: 0;
      padding: 10px;
      word-break: break-all;
      resize: horizontal;
    }
  </style>
</head>
<body>
  <div class="stretching-column">
    <div class="left">
      <div class="resize-bar"></div>
      <!-- <div class="resize-line"></div> -->
      <div class="resize-text">ABCDEFGHIJKLMNOPQRSTUVWXYZ</div>
    </div>
    <div class="right">ABCDEFGHIJKLMNOPQRSTUVWXYZ</div>
  </div>
</body>
</html>